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On November 24, 2021, a new severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variant assigned to the lineage B.1.1.529 (Omicron) was first reported to the World Health Organization from South Africa. Despite the co-circulation of several SARS-CoV-2 variants, co-infection by different variants is not commonly identified. Here, we report two cases of SARS-CoV-2 co-identifications with the Omicron and Delta variants. ispartof: INTERNATIONAL JOURNAL OF INFECTIOUS DISEASES vol:122 pages:212-214 ispartof: location:Canada status: published

Video Abstract Download : Download video (50MB) Lung transplantation from a donor previously infected with SARS-CoV-2

Summary Background Ten-valent and 13-valent pneumococcal conjugate vaccines (PCVs) have shown important benefits by decreasing invasive pneumococcal disease caused by vaccine serotypes. Belgium had an uncommon situation with sequential use of PCV7, PCV13, and PCV10 in the childhood vaccination programmes between 2007 and 2018. We aimed to analyse the changes in incidence of invasive pneumococcal disease and serotype distribution in children throughout this period. Methods Streptococcus pneumoniae isolates were obtained from patients with invasive pneumococcal disease in Belgium between 2007 and 2018 by the national laboratory-based surveillance. Paediatric invasive pneumococcal disease incidence, serotype distribution, and antimicrobial susceptibility were analysed in periods during which PCV7 (2009–10), PCV13 (2013–14), both PCV13 and PCV10 (2015–16), and PCV10 (2017–18) were used. Incidence rates and trends were compared. Vaccination status was collected. For a subset of serotype 19A isolates, multilocus sequence type was identified. Findings After a decrease in PCV7 serotype invasive pneumococcal disease was observed during the PCV7 period, total paediatric invasive pneumococcal disease incidence significantly declined during the PCV13 period (−2·6% monthly, p Interpretation After a significant decrease during the PCV13 period, paediatric invasive pneumococcal disease incidence increased again during the PCV10 period. This observation mainly resulted from a significant increase of serotype 19A cases. During the PCV10 period, dominant serotype 19A clones differed from those detected during previous vaccine periods. Whether changes in epidemiology resulted from the vaccine switch or also from natural evolution remains to be further elucidated. Funding The Belgian National Reference is funded by the Belgian National Institute for Health and Disability Insurance and the whole genome sequencing by an investigator-initiated research grant from Pfizer.

ispartof: CLINICAL MICROBIOLOGY AND INFECTION vol:28 issue:8 pages:1172-1173 ispartof: location:England status: published

ObjectivesTo better understand the conditions which have led to one of the largest COVID-19 outbreaks in Belgian nursing homes in 2020.SettingA nursing home in Flanders, Belgium, which experienced a massive outbreak of COVID-19 after a cultural event. An external volunteer who dressed as a legendary figure visited consecutively the 4 living units and tested positive for SARS-CoV-2 the next day. Within days, residents started to display symptoms and the outbreak spread rapidly within the nursing home.MethodsWe interviewed key informants and collected standardized data from all residents retrospectively. A batch of 115 positive samples with a Ct value of 2 sensors.ResultsTimeline of diagnoses and symptom onsets clearly pointed to the cultural event as the start of the outbreak, with the volunteer as index case. The genotyping of positive samples depicted the presence of one large cluster, suggesting a single source outbreak.The global attack rate among residents was 77% with a significant association between infection and presence at the event. Known risk factors such as short distance to or physical contact with the volunteer, and wearing of a mask during the event were not associated with early infection. The ventilation assessment showed a high background average CO2 level in four main rooms varying from 657 ppm to 846 ppm.ConclusionsOur investigation shows a rapid and widespread single source outbreak of SARS-CoV-2 in a nursing home, in which airborne transmission was the most plausible explanation for the massive intra-facility spread. Our results underscore the importance of ventilation and air quality for the prevention of future outbreaks in closed facilities.

The emergence of SARS-CoV-2 variants of concern (VoCs) has exacerbated the COVID-19 pandemic. End of November 2021, a new SARS-CoV-2 variant namely the omicron (B.1.1.529) emerged. Since this omicron variant is heavily mutated in the spike protein, WHO classified this variant as the 5th variant of concern (VoC). We previously demonstrated that the other SARS-CoV-2 VoCs replicate efficiently in Syrian hamsters, alike also the ancestral strains. We here wanted to explore the infectivity of the omicron variant in comparison to the ancestral D614G strain. Strikingly, in hamsters that had been infected with the omicron variant, a 3 log10 lower viral RNA load was detected in the lungs as compared to animals infected with D614G and no infectious virus was detectable in this organ. Moreover, histopathological examination of the lungs from omicron-infecetd hamsters revealed no signs of peri-bronchial inflammation or bronchopneumonia. Further experiments are needed to determine whether the omicron VoC replicates possibly more efficiently in the upper respiratory tract of hamsters than in their lungs.

Marburg virus (MARV) is the only known pathogenic filovirus not belonging to the genus Ebolavirus. Minigenomes have proven a useful tool to study MARV, but all existing MARV minigenomes are dependent on the addition of an exogenous T7 RNA polymerase to drive minigenome expression. However, exogenous expression of a T7 polymerase is not always feasible and can act as a confounding factor in compound screening assays. We have developed an alternative minigenome that is controlled by the natively expressed RNA polymerase II. We demonstrate here the characteristics of this new system and its applicability in a wide range of cell types. Our system shows a clear concentration-dependent activity and shows comparable activity to the existing T7 polymerase-based system at higher concentrations, also in difficult-to-transfect cell lines. In addition, we show that our system can be used for compound screening in a 96-well format, thereby providing an attractive alternative to previously developed MARV minigenomes. ispartof: ANTIVIRAL RESEARCH vol:185 ispartof: location:Netherlands status: published

Because of the enormous variation in their genome sequence, genotyping enteroviruses by standard methods can prove to be quite challenging. Nanopore sequencing offers the potential to overcome the limitations of older techniques, but thus far, only amplicon-based strategies have been used to sequence complete enterovirus genomes. By combining a sequence-independent, single primer amplification (SISPA) for cDNA generation with next-generation sequencing using the Oxford Nanopore MinION, complete enterovirus genomes can be obtained in an easy-to-use, sequence-independent manner. To demonstrate its usability, we applied this technique to determine the complete genome sequence of an enterovirus C104 strain, representing the first documented occurrence of this uncommon enterovirus strain in Belgium.

Background Recently, several novel hepatitis B virus (HBV) subgenotypes have been introduced that do not meet proper definition of “subgenotypes”. In particular for HBV genotype A, such novel subgenotypes have been reported. Objective To comprehensively reanalyse all HBV subgenotypes A, and to propose a novel, consistent alternative for HBV classification. Study design All HBV full-length genome subgenotypes A1–A6 were reanalysed using phylogenetic reconstruction and genetic distance calculation in order to study their evolutionary relationships. Results Phylogenetic analysis based on the complete genome sequence of subgenotype A strains revealed four distinct clusters supported by high bootstrap values, whereas only the three groups A1, A2 and A6 could be assigned as subgenotypes. Previously introduced subgenotype A3, “tentative A4” and A5 clustered together in one main branch and were designated as “quasi-subgenotypes”. Also genetic distances failed to classify these three groups as definite subgenotypes. These results advocate for a new classification of HBV genotype A into subgenotype A1, A2, “quasi-subgenotype A3” and A4. Conclusion Detailed phylogenetic analysis of the complete genome sequences demonstrates that some of available HBV genotype A strains may not be considered as definite “subgenotypes”. These strains, which are mainly of African origin, could be considered as “quasi-subgenotypes” which puts them in between the “clade” and “subgenotype” definition. Geographical origin may have a key role in further classification of HBV subgenotypes.

Background Genome diversity of hepatitis B virus (HBV) is prominent among DNA viruses; which, allowed the virus to be genetically classified into eight genotypes and several subgenotypes. Objective To introduce and to characterize a novel subgenotype HBV, classified as A6. Study design HBV full-length genomes were isolated and sequenced from three African-Belgian patients chronically infected with the virus. Using phylogenetic reconstruction and genetic distance calculation, the evolutionary relationships of the novel strains were investigated. Results Phylogenetic analysis based on complete genome sequences of genotype A strains revealed distinct clusters supported by high bootstrap values. The three African-Belgian strains clustered separately from the other known A subgenotypes (A1–A5) with maximal bootstrap support (100%). The mean inter-subgenotypic nucleotide divergence over the complete genome sequence between the novel A6 strains and A1–A5 was higher than 4%. Conclusion Phylogenetic analysis of the complete genome sequences yielded maximal bootstrap value support for nodes that establish the new lineage as a novel subgenotype. In addition, nucleotide divergence more than 4% based on full-length genome of the virus, clearly demonstrated that the three African-Belgian strains belonged to a novel subgenotype of HBV, which was assigned as “A6”. Noteworthy, the phylogeny of genotype A demonstrated that the A6 is a basal lineage that diverged earlier from the other African subgenotypes of genotype A.

Background Hepatitis B virus (HBV) is primarily transmitted from mother to child, by sexual contact, intravenous drug abuse, or unsafe health care-related injection practices. Despite increased safety efforts, nosocomial acquired hepatitis B infection remains problematic. Objectives A large HBV outbreak was investigated comprising 36 patients with acute HBV infection in a primary care physician's practice. Study design In a retrospective study (2003–2008), 36 serum samples from patients with acute HBV infection were collected. They had received several injections by the same physician at least 3 months before the onset of clinical symptoms. As a control group, sera were collected from HBV patients from other physicians from the same province. Full-length HBV genomes were amplified and were phylogenetically analysed. Results HBV complete genomes of 32 patients were successfully amplified and sequenced, and clustered together with the reference genotype A, subgenotype A2 strains. We also analysed 26 control HBV genotype A samples. All 32 HBV strains from the patient group clustered in a monophyletic branch with a bootstrap value of 100, whereas the control samples branched separately in another clade. The genetic distance value showed small differences within the patients group, whereas the rate within the control group was seven times higher. These observations confirm that the source of transmission was clearly different in both groups. Conclusion Maximum likelihood analysis and genetic distance calculations based on the full-length genomes of HBV strains isolated from patients and controls provided strong evidence for a common nosocomial source of infection for all 32 patient cases.

Hantaviruses, members of the family Bunyaviridae, are the causative agents of hemorrhagic fever with renal syndrome and hantavirus cardiopulmonary syndrome. Hantaviruses are currently demarcated into species based on the guidelines provided by the International Committee on Taxonomy of Viruses (ICTV). These guidelines however, are often ignored by the descriptors of novel hantaviruses. With this study we attempted to refine the second ICTV guideline for hantavirus species demarcation by phylogenetically analyzing all in Genbank available complete sequences derived from the S, M or L segments of hantaviruses. S and M segment amino acid sequence comparison allowed clear and unequivocal distinction between different hantavirus species, and lead us to propose additional criteria for the demarcation of hantavirus species (S segment amino acid distance >10% or M segment amino acid distance >12%) and hantavirus groups (S segment amino distance >24% or M segment amino acid distance >32%). With this study, we propose to adjust the second rule of the ICTV classification guidelines ("a 7% difference in amino acid identity when comparing the complete S segment and M segment sequences") to a more appropriate rule, "a 10% difference in S segment similarity and a 12% difference in M segment similarity based on complete amino acid sequences" in accordance with the current situation in the hantavirus field.

Hantaviruses, which are mainly rodent-borne viruses, cause hemorrhagic fever with renal syndrome in the Old World, and hantavirus pulmonary syndrome in the New World. A neutralization test based on quantitative RT-PCR, the replication reduction neutralization test (RRNT), was developed for efficient detection of hantavirus-neutralizing antibodies. The effectiveness of the RRNT was evaluated by examining several hantaviruses and hantavirus-specific convalescent human serum samples. All convalescent serum samples tested by RRNT caused significant decreases in hantavirus genomes with only one specific hantavirus species, which allowed a straightforward identification of the related hantavirus. The results obtained by RRNT were completely comparable with the results obtained by focus reduction neutralization test (FRNT). The RRNT approach is a reliable and rapid alternative for FRNT, hitherto considered as the gold standard for hantavirus serology.

We report on chloroquine, a 4-amino-quinoline, as an effective inhibitor of the replication of the severe acute respiratory syndrome coronavirus (SARS-CoV) in vitro. Chloroquine is a clinically approved drug effective against malaria. We tested chloroquine phosphate for its antiviral potential against SARS-CoV-induced cytopathicity in Vero E6 cell culture. Results indicate that the IC50 of chloroquine for antiviral activity (8.8 +/- 1.2 microM) was significantly lower than its cytostatic activity; CC50 (261.3 +/- 14.5 microM), yielding a selectivity index of 30. The IC50 of chloroquine for inhibition of SARS-CoV in vitro approximates the plasma concentrations of chloroquine reached during treatment of acute malaria. Addition of chloroquine to infected cultures could be delayed for up to 5h postinfection, without an important drop in antiviral activity. Chloroquine, an old antimalarial drug, may be considered for immediate use in the prevention and treatment of SARS-CoV infections.

Recently, we proposed a new classification for ‘subgenotype A’ of hepatitis B virus (HBV), in which the novel ‘quasi-subgenotype A3’ group comprising HBV ‘subgenotype A3', ‘tentative A4', and A5 was introduced. Newly ‘Tentative subgenotype A7’ strains from Cameroon were introduced by Hubschen et al. However, our meticulous phylogenetic analysis demonstrated that these isolates should also be classified into ‘quasi-subgenotype A3'. Such misclassification can be avoided by following established principles for HBV subgenotyping. Moreover, their close evolutionary relationship with A3 highlights our hypothesis that geographical origin may be an important factor in further classification of HBV subgenotypes.

a Department of Microbiology and Immunology, Laboratory of Clinical and Epidemiological Virology, Rega Institute for Medical Research, KU Leuven, Leuven, Belgium b Molecular Biology and Immunology Department, Fundacion Instituto de Inmunologia de Colombia (FIDIC), Bogota, Colombia c Basic Sciences Department, School of Medicine and Health Sciences, Universidad del Rosario, Bogota, Colombia d Department of Zoology, University of Oxford, South Parks Road, OX1-3PS Oxford, United Kingdom e Department of Molecular Microbiology and Immunology, Keck School of Medicine, University of Southern California, Harlyne J. Norris Cancer Research Tower, Los Angeles, CA 90033, USA f Middle East Liver Disease Clinics, Sepahbod Gharani Ave, 14,155-3651 Tehran, Iran g Blood Transfusion Research Centre, High Institute for Research and Education in Transfusion Medicine, Hemmat Exp. Way, 14,665-1157 Tehran, Iran h Centro de Malaria e Outras Doencas Tropicais and Unidade de Saude Publica Internacional e Bioestatistica, Instituto de Higiene e Medicina Tropical, Universidade Nova de Lisboa, Lisbon, Portugal